Altered postural regulation of foot skin oxygenation and blood flow in patients with type 2 diabetes mellitus
ABSTRACT Although skin oxygenation is an important factor in the development and healing of foot ulcers, its regulation was not fully understood. We studied changes in foot skin oxygenation and blood flow during postural changes in patients with type 2 diabetes mellitus.
Skin oxygenation was measured using transcutaneous oxygen pressure (TcPO(2)) and skin blood flow by laser Doppler flowmetry in 40 patients with type 2 diabetes mellitus without evidence of peripheral arterial disease and 13 healthy control subjects.
TcPO(2) in the supine position was significantly lower in patients with type 2 diabetes mellitus compared with control, although skin blood flow was not different. In the sitting position, TcPO(2) significantly increased in control and diabetic patients. The postural change-related increase in TcPO(2) was significantly enhanced in diabetic patients. On the other hand, skin blood blow significantly decreased in the sitting position from the supine position in control subjects but remained stable in diabetic patients. Orthostatic drop in systolic blood pressure correlated negatively with TcPO(2) in the supine position while correlated positively with %change in TcPO(2) and blood flow by postural changes.
The present study demonstrated the dissociated regulation of skin oxygenation and blood flow in response to leg dependency. Impaired postural vasoconstriction was associated with altered regulation of skin oxygenation probably due to sympathetic vascular dysfunction in diabetic patients.
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ABSTRACT: Aims The assessment of transcutaneous oxygen pressure (TcPO2) may serve as a non-invasive and lower-cost alternative to nerve conduction studies (NCSs) for the diagnosis of diabetic peripheral neuropathy (DPN). The aim of this study was to determine whether the measurement of TcPO2 is useful for evaluating DPN. Methods We performed a cross-sectional study of 381 consecutive hospitalized diabetic patients classified by clinical examination and NCS as having DPN. Anthropometric and metabolic parameters were assessed. The TcPO2 examination was performed in both supine and sitting positions. Results Three hundred and one patients had DPN. The TcPO2 in both the supine and sitting positions was highest in the Non-DPN group and lower in the confirmed DPN group than the other three groups (p < 0.001). The Non-DPN group had the lowest sitting-supine position difference in TcPO2 among the groups (p < 0.001). The risk factors strongly associated with DPN included sitting-supine position difference in TcPO2 (OR =4.971, p < 0.001), diabetic retinopathy (DR) (odds ratio [OR] =3.794, p =0.002), and HbA1c (OR =1.534, p =0.033). The area under the curve (AUC) of the sitting-supine position difference in TcPO2 was 0.722 and revealed an optimal cutoff point for the identification of DPN (19.5 mmHg) that had a sensitivity of 0.611 and a specificity of 0.738 based on AUC analysis. Conclusions This large study of diabetic patients confirms that the sitting-supine position difference in TcPO2 is higher in DPN patients than control subjects, indicating that TcPO2 examination is a promising valuable diagnostic tool for DPN.Diabetes Research and Clinical Practice 09/2014; 105(3). DOI:10.1016/j.diabres.2014.05.012 · 2.54 Impact Factor
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ABSTRACT: The aim of this study was to evaluate foot temperature in type 2 diabetic patients with vs. without peripheral neuropathy. The study included 30 patients (group A: 16 men, mean age 63.23+/-7.02 years) with peripheral neuropathy and 30 patients (group B: 17 men, mean age 62.37+/-6.73 years) without peripheral neuropathy. Neuropathy was diagnosed by the Diabetic Neuropathy Index (DNI). Foot temperature was measured with a handheld infrared thermometer (KM 814, Kane-May, UK) on the mid-dorsal aspect of the foot (dorsal temperature) and on the plantar aspect of the foot at the level of the first metatarsal head (plantar temperature). Dorsal temperature was significantly higher in group A than in group B (right foot 32.89+/-1.02 degrees C vs. 31.2+/-1.07 degrees C, p<0.001). The same significant difference was observed for the plantar temperature (32.2+/-0.94 degrees C vs. 30.7+/-1.07 degrees C, p<0.001). In both groups, a significant positive correlation was observed between dorsal and plantar temperature (group A: r (s)=0.913, p<0.001; group B: r (s)=0.956, p<0.001). Finally, in group A, DNI score showed a significant positive correlation with dorsal temperature (r (s)=0.856, p<0.001), as well as plantar temperature (r (s)=0.859, p<0.001). CONCLUSIONS: Foot temperature is significantly higher in type 2 diabetic patients with neuropathy as compared to those without neuropathy. In patients with neuropathy, a significant positive correlation is observed between foot temperature and clinical severity of neuropathy.Experimental and Clinical Endocrinology & Diabetes 09/2008; 117(1):44-7. DOI:10.1055/s-2008-1081498 · 1.76 Impact Factor
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ABSTRACT: Diabetic foot disease and ulceration is a major complication that may lead to the amputation of the lower limbs. Microangiopathy may play a significant role in the pathogenesis of tissue breakdown in the diabetic foot. However, the precise mechanisms of this process remain unclear and poorly understood. Microvasculature in the skin is comprised of nutritive capillaries and thermoregulatory arteriovenous shunt flow. It is regulated through the complex interaction of neurogenic and neurovascular control. The interplay among endothelial dysfunction, impaired nerve axon reflex activities, and microvascular regulation in the diabetic patient results in the poor healing of wounds. Skin microvasculature undergoes both morphologic changes as well as functional deficits when parts of the body come under stress or injury. Two important theories that have been put forward to explain the abnormalities that have been observed are the haemodynamic hypothesis and capillary steal syndrome. With advances in medical technology, microvasculature can now be measured quantitatively. This article reviews the development of microvascular dysfunction in the diabetic foot and discusses how it may relate to the pathogenesis of diabetic foot problems and ulceration. Common methods for measuring skin microcirculation are also discussed.Diabetes/Metabolism Research and Reviews 10/2009; 25(7):604-14. DOI:10.1002/dmrr.1004 · 3.59 Impact Factor